safety clamp fob dkill collars



Aprl 8, 1.952

w. A. ABEG-G -sAFETY CLAMP FOR DRILL' COLLARS Filed Sept. 15, 1947 nventor l WAHL-R6' ABL-6G.

E 20 u /Q/wu/a /h (Ittorneg Patented Apr. 8, 1952` s PATENT OFFICE SAFETY CLAMP FORVDRILL COLLARS Walter A. Abegg, Los Angeles,` Calif., assignor, by mesne assignments, to Abegg & Reinhold Co., Los Angeles, Calif., a corporation of California Application September 15, 19497,` Serial No. 774,168

8 Claims. l

This invention relates to oil well equipment,

and particularly pertains to a safety clamp for drill collars. In' the course of operation of drilling'oil wells it is necessary at times to grip the string of pipe in a manner to support the drill string so that it may be raised or lowered incident to the drilllingop'erations. It is desirable to provide a clamp structure which will embrace a' relatively small `area of the drill string to be clamped and which at the same time will make it 'possible for the collar'to be quickly placed in position and to be quickly and easily removed therefrom. It is the principal object of the present invention, there- Ifore, to provide a safety clamp which maybe .easilyplaced in position or removed therefrom, and which is formed of articulately connected -members adapted to collectively embrace a drill collar and to positively grip and hold the same. The present' invention contemplates the pro- ,vision'of a safety clamp fortdrill collars which comprises a plurality of clamp segments articulately connected together and carrying positive pipe engaging means, the segments being provided with means whereby the composite strucf ture may be positively set in its gripping position.

The invention is illustrated by way of example in the accompanying drawings in which:

` Figure 1 is a view in plan showing, the safety clamp with which the presentinvention is concerned.

Fig. 2 is 'a View in side elevation showing the clamp, the drill pipe being indicated by dotted lines. "Fig 3 is a vertical section through one of the body segments and the contained gripping unit, taken on line 3-3 of Fig. 1. Fig. 4 is a View of the face of an individual gripy pingv unit,.`including a gripping support and 'carrie'd gripping elements, taken in the direction of arrow 4 in Fig. 3.

Referring more particularly to the drawings, vIII indicates a drill string to be gripped by the clamping device, whichis here generally indicatedat II.` The clamping device comprisesv a center. segment I2 and side segments I3 and lll. `Viewed in plan, the center segment is arcuate in shape andis formed at its opposite ends with lugsllZ,v kIntermediate the ends of the centersegment [is a, boss structure I6 which normally assumes avertical position. This boss is of a diameter, greater than the width of the segment I2 and 'is.eccentricallydisposed with relation to said seg- -mentsoi that the upperA outer edge of" thev boss 2 f Y coincides substantially with the outer edge of a horizontal flange element I1 which is'connected to a parallel flange element I8 by a vertical web I9 to form the body oi the segment I2. By reference to Fig. 2 of the drawing it will be seen that the outer wall of the boss I6 extends downwardly and inwardly. The angle of the outer wall is vhere indicated as being at approximately 91/'2 degrees to the vertical. An eccentric bore 20 eX- tends downwardly in the boss I6. This bore is yeccentric to the upper end of the'boss I5 and its center is spaced toward the inner edge of the segment I2 a shorter'distance than the radius of the bore. This will cause a throat 2I to be out through the inner face of the boss, for a purpose to be hereinafter described. In Fig. 1 of 'the drawing'the incompleted portions of the outer circumferenceof the boss II and the bore 20 are indicated by dotted linesV so that the relative `eccentricity of these bores can be seen as well as the relationship ofthe circles to the inner arcuate face of the clamp segment I2. The lower end of 'the bore 20 is closed and is formed with a cylindrical seat 22 to receive a `helical expansion spring 23. The expansion spring 23 extends upwardly and engages the eye 24 of a pin 25. The pin 25 extends upwardly through agrip support 2S'. The grip support 26 is substantially cylindrical and agrees in configuration with the bore 2U. Thus a segment willv be cut from the inner face of the cylindrical grip support agreeing in width with the opening 2i in the side of the bore 20. lThe springs 23 will tend to urge the grip support 2li upwardly and in view of theh fact that the width ofthe opening 2I is less than the diameter Y of the` bore 20 it is obvious that thel grip support will be free to rotate within the bore 20 in adapting itself'to the pipe to be gripped.

Formed. in the flat face 2l of the grip support is a series of vertically adjacent partial circular recesses 23. Extending into the grip support vfrom the center of each recess is a reduced bore 29. As shown in Fig. l of the drawing, it will be seen that the ends of the bores 29 intersect the central axis of the grip support 26. Extending longitudinally of the grip support 2E and intersecting each of the bores 29 is a small bore 30 which is' of a ,diameter to receive the pin 25. v'Ifhel upper end of the pin 25 has a T-shaped head 3l whichengages the upper end of grip support 2li to support the pin in fixed relation to the grip support. Mounted within thel circular recesses 28 'and `thebores 29 are gripping elements 32with their stems 33. The stems 33 extend into the `Abore ,29 and are formed with a central opening 34 through them which registers with the bore 30 previously described so that the pins 25 wil pass through the stems 33 of the gripping elements to prevent displacement of the gripping elements and also to prevent their rotation. The faces of the gripping elements 'may be of any desired design to cause impingement of the face of the gripping elements with the surface of the pipe IIl, thus preventing longitudinal or rotational displacement of the pipe when gripped. Formed at opposite sides of the boss I6A and ex;- tending upwardly therefrom are lugs 35 which have openings 36 through them to receive a transverse cotter pin 31 for limiting` upward movement of grip support 26. The rotation of grip support 26 within its guiding bore iSlimited by engagement of gripping elements 32 with the body of the segment. The permittedrrotative movement of grip support 26 is just sufficient to enable its lateral adjustment to nt the different sizes `of pipe that mayl be encountered.

'HIhe side segments: I3 and I4 are substantially complementary to each other. Each side segment is formed withparallel ribs 38 and 39 which at one end provide lugsdll and 4I between which Ia lu`g42 ofthe center segment I2 extends. The lug 4 2 is forined with a center bore 43 in register with bres i4 and 45 of the lugs 40 and 4I. These registering bores receive a hinge pin 46 by which ythe,A side segments I4 and I5 are articulately connected to the center segment I2. The main body oi` 4eacli of the segments I3 and I4 is arcuate when vconsidered plan, and at a point interrlliediate their arcuatelengths'other bosses I6 are formed which are identical in construction with the boss Ifc'rr'n'ed centrally of the intermediate segment I 2. 'Ilh'ese bosses carry grip supports 26, each 'one of which provides amounting for va plus ralit'lyof v gripp'ir'ig elements 32. Like parts of the boss and gripping structures on the side segments willibe given the same numbers as the same parts on the center segment I2. A

The side segment I3 is formed with an arm, 51 which is forked tol receive an intermediate bar 58. This bar is pivoted in position by a pivot pin 59, "the axis f whichi'is parallel tothe center axis of the safety clamp.` lThe contiguous end of the side segment y'I4 earries an arm, which under normal clamping conditions is substantiallyparand to theariri t1 and is indicated ateo. The

aiQInIi attits free` end is formed with a fork Y(il ,whichis at kright angles to the Yaxis of the pin 53, V'ifheou'terlface of the fork l6I is arcuate and coijigayedi as indicated vat 62, Land receives a washer 63, which has a complementary convex face on one 'Side and a ati'aoe -65 jon its other side. The hay sa is formed, at que free end 'with an eye66. rIhis eye 66 serves to receive the :pivot pinSSwhen the 'clamp is to be expanded for use onia larger diameter of pipe. The eppositeend of` the bar isformed ywith 'a lt'l'leaded cylindrical portionfi which receives a wing nut '681. The length of thethreaded lportion vIiI is such asto insure thaty when the wing nu't is loosened the wasiiei ,6.3 may swing over the pointed edges 69 f theforked portion'l so that the'arms "51 and may be Yswung apart, and so ythat the safety clamp maybe Vremoved from its lernbracing posi- Ation around the pipe ID. yloops 1u and 1 1 are secured to opposite "sides 'of the side segments `I'3 and lIll of the clamp and are disposed in a substantially diametrical relation to 'eachother at opposite sides of the normal 'center of the'cla'in'p. i l

'To permit use of the clamp 'on'pipesof widely A pair of f'supprting i varying sizes, it is "*nportant that the bar or link 58 be positioned far enough radially outwardly from the pipe being gripped to prevent engagement of the bar with the pipe when the clamp is opened to a large diameter condition. For this purpose, the bar 58 is preferably so mounted that when the clamp is in its substantially smallest diameter condition of Fig.r1, that is, when the end segments I3 and I4 are in approximately their closest relation, the portion of the bar extending between the end segments is radially spaced from a line II3 extending between the centers of the gripping faces of the gripping elements carried by those end segments a distance X which is approximately as great as the distance Y from that line to the gripping face of the third and most remote gripping element.

In operation of the present invention the safety clamp is assembled as shown in the drawings. When it is to be used supporting reins may be provided to engage the loops 'I0 and II and to thus carry the weight of the safety clamp as well as the weight of the string of pipe which may be supported by the clamp. The clamp is placed in position by spreading the segments apart so that there ywill be a space between the members 5l and 60 to accommodate the pipe. When the pipe is in its properl position between the seg'- ments the portions 51 and 60 may be drawn together, after which the bar 58 carrying the screw 61 may be swung on the pivot 59 to place the threaded screw 6l between the forked arm 6I. The wing nut may then be tightened, and as -this takes place the gripping elements 32 will 'be drawn against the cylindrical face of the drill string. When the arms 51 and 66 have been drawn together as tightly as possible by the wing nut 68 it will be `evident that the `gripping elements '32 will be forcibly held against the face of the drill pipe, and that any serrations on the faces of the 4gripping elements will to someextent mpinge in the, surface of the drill pipe. When the weight o'f the drill string is imposed upon the safety clamp it will be evident that s ucient engagement is present between the drill 'string and the gripping elements so that the gripping elements will not slip and so that the weight will tend 'toy force the gripping elements 'and their holders 26 downwardly in the bores 20 against the expansion of springs 23. Thus, due to the fact that the bores 20 are inclined downwardly and inwardly it will be obvious thatthe grip supports 26 and the gripping elements 32 will be forced downwardly and inwardly to increase their grip- Ding action. When it is desired to remove the safety Vcljanip the string of pipe is temporarily supported by the slips in the'rotary table so that the weight will be relieved from the safety clamp. The wing nut 68 vmay 'thenbe loosened and s wung to a free position withjrelation to jthe arms of the fork `6I, after which the articulate'clamp structure may be unwrapped from around the .drill stem. Y Y

It is obvious that the safety 4clamp here disclosed provides simple and eiective imeans whereby a pipe Amay vbe positively gripped and supported, land which I'neans is strong in Yconstructionandmay be easily manipulated toplaoe itin a gripping positionor to remove'it therefrom. t While I have shown'th'e preferred 'form 'of my invention as now known to /me,'it will beunderstood that various'changes may be vmade 'in com- 4bination, construction 'and arrangement 'of parts by those 'skilled `fin the art, without 'departing 'from the spirit of the invention as claimed.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

essentially cylindrical bore extending angularly downwardly and inwardly relative to the vertical YVaxis ofthe clamp and pipe, each of said segments having an inner substantially vertical iace lying in ajplane spaced from the axis of the correi spondingbore a distance less than the bore radius to form an opening at the inside of thesegment extending along the length of the bore, a plurality of essentially cylindrical gripper mounting members guided within said angular bores respectively for both rotation and axial movement therealong, springs beneath said mounting members'urging them upwardly within said bores,

said mounting members having inner iaceslying substantially in the'planes of said inner faces of the ,corresponding segments in predetermined y' positions 'of the mounting members, anda plurality of gripper elements carried by said mounting members and projecting inwardly from said inner faces thereof, each of said gripper elements I.having an inner. gripping face extending essentially axially of the clamp and at an angle to said downwardly and inwardly extending axis of the associated mounting member, said body, mounting members and gripper elements being open toextension entirely through the body of f an externally straight `cylindrical pipe portion engaged by said gripping faces of the gripper elements.

A2. A safety clamp for attachment to a vertically extending well pipe comprising a body in- 4cluding a plurality of articulately connected arcuate segments adapted to extend about the pipe, means for releasably and adjustably interconnecting 'the end ones of said segments to fasten the body about the pipe, each of said segments containing an essentially cylindrical bore extending angularly downwardly and inwardly i relative tothe vertical axis of the clamp and pipe,

eachffof said segments having an inner substantially vertical face lying in a horizontally arcuate plane spaced from the axis of the corresponding bore a distance less than the bore radius to form ancperiing at the inside of the segment extending along the length of the bore, a plurality of essentially cylindrical gripper mounting members guided within said angular bores respectively Lfor ,both rotation and axial movement therealong, Vsprings Abeneath said mounting members urging them upwardly within said bores, said mounting members having inner faces lying substantially Vin the planes of said inner faces of the corresponding segments in predetermined positions of the mounting members, and a plurality of gripper elements carried by ysaid mounting members and projecting inwardly from said inner faces there-f of, each of said gripper elements having an in- 'I ner enlarged head portion presenting a serrated arcuate inner gripping face extending essentially axially of the clamp and at an angle to said downwardly land inwardly extending axis of the associated mounting member.

3. An adjustable device for gripping a vertically extending well pipe comprising a body including a series of pivotally interconnected segments adapted to Vextend about the pipe, `means for vreleasably interconnecting end segments* of saidv series to fastenv the segments about thev pipe and adjustable for fastening the segments about pipes of different diameters; apluralityof gripping units carried at therinside of said segments respectively for Yengaging and gripping the pipe,4

said gripping units having inner gripping faces essentially curved in correspondence with the outer surface of one size of pipe to be gripped, the individual gripping 'units being free for both swinging movement about `and movement axially along circularly spaced individual axes extending angularly downwardly and inwardly relative to the vertical axis of the body and pipe, and connections individually mounting said gripping units to said body segments for said swinging and axial movements` relative thereto, whereby the 4. `.an adjustable device for gripping avertically extending well pipe comprising a body-including a series of pivotally interconnected seg- `ments adapted to extend' about the pipe, means for 'releasably interconnecting end segments of said series to fasten the segments about the pipe and adjustable for fastening the segments about pipes ofA diierent diameters, said segments Icontaining individual partial cylindrical boresextending angularly downwardly and inwardly relative to thevertical axis of the body and pipe and open along the inner sides of the segments, and a plurality of gripping units carried at the inside of said segments respectively for engaging and gripping the pipe, said units having essentially cylindricaly outer portions mounted within said cylindrical bores for both limited rotation and movement axially ofthe bores, whereby the gripping units are free for individualV lateral movement to adjust themselvesuto different sizes of pipe and are automatically wedged inwardly into tight engagement with the pipe upon relative downward movement thereof, said body andl gripping units being open to extension entirely vthrough the-body of an externally straight cylindrical pipe portion engaged by said gripping faces of the units. Y

5. An adjustable device for gripping a vertically extending well pipe comprising a body including al series of pivotally interconnected'segments adapted to extend about the pipe, means for releasably interconnecting end segments of said series to fasten the segments about the pipe and adjustable for fastening the segments about pipes of different diameters, said segments containing individual partial cylindrical bores extending angularly downwardly. and inwardly relative to the vertical axis of the body and pipe and open along the Ainner sides of the segments, a plurality of gripping units carried at the inside of said segments respectively for engaging and gripping the pipe, said gripping units having inner gripping faces essentially curved in correspondence with the outer surface of one size of ping units are free 'for individual lateral move- 'ment to adjust themselves to different sizes of pipe and are automatically wedged inwardly into tight lengagement with the pipe upon relative downward movement thereof, said body and gripging units being open to extension entirely through the body of an externally Vstraight cylindii'cal pipe portion engaged by said gripping faces ofY the units, and a plurality of springs urging said gripping units upwardly along said axes'.

6l A safety clamp for attachment to a vertically extending well pipe comprising a body including a ser-ies of only three arcuate pivotally interconnected segments adapted to extend about the pipe, means for releasably interconnecting end segments of said series to fasten the segments about the pipe and adjustable for fastening the segments about Vpipes of different diameters, and three gripping units carried only one at the inside of each segment for engaging and Agripping the pipe, said gripping units having inner gripping faces essentially curved in correspondence with the outer surface of one size of pipe to be gripped, said segments containing individua-l `partial cylindrical bores extending downwardly and inwardly relative to the .vertical axis of the clamp and pipe and open along the inner sides of the segments, said units hav- 'ing partial cylindrical outer portions mounted Within said cylindrical b'ores for both limited rotation and movement axially of the bores, whereby the gripping units are free for individual lateral movement to adjust themselves to different -sizes of pipe and are automatically wedged inwardly into tight engagement with the pipe upon 'relative downward movement thereof, said body and gripping units being op'en to extension entirely through the body of an externally straight cylind'r'cal pipe portion being engaged by said gripping faces of the units.

7. A safetyclamp for attachment to a vertically extending Well pipe comprising a body including a series of only three arcuate pivotally interconnected segments adapted to extend about the pipe, means for releasably interconnecting end segments of said series to fasten the segments about the pipe and adjustable for fastening the segments about pipes of Adiierent diameters, three gripping units carried only one at the inside of each segment for engaging and gripping the pipe, said gripping units having inner gripping faces essentially curved in correspondence with the outer surface of one size of pipe to be gripped, said segments containing individual partial cylindrical bores` extending downwardly and inwardly relative to the vertical axis of the clamp and pipe and open along the inner sides of the segments, sa-id bores being open at their upper ends and partially closedat their lower ends. said units having partial cylindrical outer portions mounted within said cylindrical bores for both limited rotation and movement axially of the bores, whereby the gripping units are free for individual lateral movement to adjust themselves to diierent sizes of pipe and are automatically wedged inwardly into tight engagement with the pipe upon relative downward movement thereof, said `body and gripping units being open to extension entirely through the body of an externally straight cylindrical pipe portion being engaged by said gripping faces of the units, three springs contained within vthe lower ends of said bores and acting to urge said grippingunits upwardly 'and outwardly, and means limiting upward 'mcvement of said units within the bores.

8. An adjustable safety clamp for gripping 'a vertically extending well pipe comprising 'a body including a series of only three pivotally interconnected segments adapted to extend aboutthe pipe and containing individual essentiallyrcylindiical bores extending angularly downwardly 'and inwardly relative to the Vertical axis of the body and pipe, a link pivotally carried by one of the end segments of said series and adapted to releasably interconnect the t'wo end segments in any of a plurality of adjusted conditions to clamp the body about any of different sizes of pipe, and only three substantially evenly circularly spaced gripping units mounted at the inside-of said segments and having essentially cylindrical outer portions mounted within said bores for both' limited rotation and movement axially of the bores, whereby each of said units is free Afor both bodily lateral movement relative to the associated segment for adjustment to different sizes of pipe and bodily movement angularly downwardly and inwardly relative to the axis of the clamp and pipe, the portion of said link extending between said end segments when retained in their closest relation being radially spaced from aline joining the centers of the gripping faces of the gripping units carried by said end segments a distance about as great asl the Adistance between said line and the face of the most distant gripping unit therefrom.

WALTER A. ABEGG.

REFERENCES CITED The following references are of record the 111e of this patent:

UNITED STATES PATENTS Number Name nate g 491,872 Canneld Feb. 14, 1893 Rigby NV. I2, 1,280,850 Robichaux oct; 8, '1918 1,499,225 Krell June 24; 1924 1,547,543 Welty July 28; 1925 1,556,094 Fletcher Oct. 6, 1925 1,560,661 Carlson ;1 Nov. 10, 1925 1,5503827 Linthwaite .ia-n. 12, 1926 1,625,540 Hertzberg Apr'. 1,9, 1927 1,664,709 Severns et al. Apr. 3, 1928 1,716,905 Smith June 11, i929 1,884,318 McLagan Dee. 1, 1931 2,030,499 Church Feb. 11, 1936 2,093,783 Vaughn Sept; 21, 1937 2,119,731 7, 1938 2,229,807 Jan. 21, 1941 2,242,573 May 20, 1941 2,301,625 a- NV; i0,- *1942 FOREIGN PATENTS Number Country Date 110,225 Great Britain Oct. 18, 1917 

